RIO NEGRO. 
113 
m 
examination by the naturalists. Its dimensions were nine feet in 
circumference; the brachial seven feet long. It proved to be the 
Acalopha medusa pelagia of Cuvier. 
On the 17th of February, we had an 
extraordinary degree of mirage or re- 
fraction of the Peacock, exhibiting three 
images, two of which were upright and 
one inverted. They were all extremely 
well defined. The temperature on deck 
was 54°, that at masthead 62°. A vessel 
that was not in sight from the Vincennes' 
decks, became visible, as in the annexed 
^ M;<*t*nzimz'Wff/;f<i 
t<^*'^*^Mnr?-*.W't*^!.!1^*^/!^y>W^W,t.t,r^ivil4lf?pt-K/-ft?tt'> 
sketch ; the land at the same time was much distorted, both vertically 
and horizontally. Barometer stood at 29-62 in. ; hygrometer 10°. 
On board the Peacock, similar appearances were observed of the 
Vincennes and Porpoise. There was, how- 
ever, a greater difference between the mast- 
yp head temperature and that on deck, the 
'JZOZZ thermometer standing at 62° at masthead, 
while on deck it was but 50°, being a dif- 
ference of 12° ; that on board the Vincennes 
differed only 8°. The sketches were taken 
about the same time : that made of the Pea- 
cock on board the Vincennes it will be seen 
was the most elongated. 
We continued beating into the passage 
between the Hermit Islands and False Cape 
Horn, and found great difficulty in passing Point Lort, from the 
very strong outward set of the tide, which we found to run with a 
velocity of five miles an hour. We were not able to make way 
against it, though the log gave that rate of sailing. After beating 
about in this channel a long and dark night, with all hands up, we 
made sail at daylight, and at half-past 6 a. m. anchored in Orange 
Harbour. Here we found the Relief and tenders, all well. 
vol. i. 29 
VINCENNES. 
